5 Query Pushdowns for Distributed SQL and How They Differ from a Traditional RDBMS — A pushdown is an optimization to improve the performance of a SQL query by moving its processing as close to the data as possible.

Isolation Repeatable Reads in Postgres vs MySQL — By default, Postgres and MySQL use different levels...

Isolation Repeatable Reads in Postgres vs MySQL — By default, Postgres and MySQL use different levels of isolation within transactions. Within a running transaction, Postgres will see changes made by other transactions once committed, whereas MySQL uses “repeatable read” where the results of a query remain consistent throughout a transaction. There’s a bit more to it than that, though, and this post deftly shows us how it all works.